Reflexes, loss

Central nervous system effects predominate in acute exposures at massive doses, whereas peripheral neuropathy is more common with lower doses.After cessation of exposure to acrylamide, most cases recover, although the course of improvement can extend over months to years and depends on the severity of exposure. Because peripheral neurons can regenerate and central axons cannot, severely affected individuals may still experience residual ataxia, distal weakness, reflex loss, or sensory disturbance. 

A disease which causes the noninflammatory degeneration of many of the peripheral nerves. It may result from (1) certain deficiency diseases, (2) metabolic diseases, (3) chemical poisoning, (4) some infective diseases, (5) a carcinoma, or (6) some rare genetic diseases. Symptoms consist of cramps, numbness, weakness, loss of reflexes, loss of positional senses, and partial paralysis. Usually the legs are affected first, and then the arms. Those deficiency diseases exhibiting polyneuropathy are beriberi, pellagra, chronic alcoholism, burning feet syndrome, and pyridoxine or pantothenic acid deficiency. 

Neurological symptoms result from demyelination of the spinal cord and are potentially irreversible. The symptoms and signs characteristic of a vitamin B 2 deficiency include paresthesis of the hands and feet, decreased deep-tendon reflexes, unsteadiness, and potential psychiatric problems such as moodiness, hallucinations, delusions, and psychosis. Neuropsychiatric disorders sometimes develop independently of the anemia, particularly in elderly patients. Visual loss may develop as a result of optic atrophy. 

Distal sensory neuropathy AIDS Subacute or chronic Distal sensory loss and neuropathic pain depressed or absent ankle reflexes Immune dysfunction macrophage-mediated axonal injury... 

Crofton KM, Zhao X. 1993. Mid-frequency hearing loss in rats following inhalation exposure to trichloroethylene evidence from reflex modification audiometry. Neurotoxicol Teratol 15 413-423. 

FIGURE 6. Histograms depicting doses of PCP and related compounds which produced (A) maximal disruption of rotarod performance (B) loss of righting reflex (C) clonic and/or toxic convulsions and (D) lethality in rats (n=6) given cumulative intravenous doses... 

Conditions that increase the evaporative loss of tears also worsen dry eye. In addition to environmental causes (Table 60-9) an abnormal blink reflex is a common cause of increased evaporative loss.30... 

Guillain-Barre syndrome is a transient neurologic disorder involving inflammatory demyelination of the peripheral nerves. The syndrome is characterized by progressive symmetric weakness of the legs and arms with loss of reflexes. Occasionally sensory abnormalities and paralysis of respiratory muscles will occur.16... 

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